Along with the popularity of flat-panel displays, consumers have increasingly higher demands upon the flat-panel displays, and flat-panel display manufacturers increasingly focus on the improvement of product quality. But the afterimage problem always affects the image quality of flat-panel displays.
Afterimage refers to a phenomenon in which, when a display device is switched to another image after an image is displayed by the display device for a long time, a ghosting image of the previous image will be left on the display device. Liquid crystal display (LCD), as one of the flat-panel display, will have residual charges due to the action of an external electric field after displaying an image for a long time, thus the LCD cannot completely display a new image when being switched to display another image and an afterimage of the original image is still left thereon, and hence the display effect of the LCD can be affected. Other flat-panel displays such as plasma display panel TV also have the similar phenomenon.
Currently, a conventional technology mainly evaluates an afterimage level by the visual comparison with an afterimage level sample. The method for determining the afterimage level by human eyes suffers from strong subjectivity, namely the determination of results is often different due to the visual difference of different people, so that the afterimage levels determined by different people are different as well, and hence the image quality of the display cannot be accurately determined, and consequently the manufacturer cannot improve the display device.
In summary, the afterimage level of a display device can be determined by human-eye observation only, and hence the accuracy is very low.